Operating lamp provided with a light pipe

ABSTRACT

A lamp arrangement for medical operating rooms. Light from a point source is focused by a spheroidal reflector on the inlet end of a light pipe, which transmits it to a reflector arrangement below. In one embodiment a straight light pipe is employed with a stepped prismatic element to direct the light upward onto a stepped reflector. In an alternate embodiment a curved light pipe is employed to transmit the light directly onto a parabolic reflector. The light rays leaving the final reflector in both embodiments are parallel and of uniform intensity.

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.XR 3772s506 1 SIZARL'JJ I RQOM' 1 United Sta 1 [111 3,772,506 Jun in er Nov. 13 l 7 g g Q! lRQT/Tl 1-r-rrm M. H 9 3 vwvnilul m awn HQCMNL: AH I OPERATING LAMP PROVIDED WITH A 3,360,640 12/1967 Seitz et a]. 240/14 GHT E 3,437,803 4/1969 Seitz et al. 240/l.4

[75] Inventor: Klaus M. Junginger, Rodenbach, FOREIGN PATENTS OR APPLICATIONS Germany 1,121,606 7/1968 Great Britain 240/14 [73] Assignee: Original Hanau Quarzlampen GmbH, Germany Primary Examiner-Richard L. Moses [22] Filed: July 6 1972 Attorney-Richard C. Sughrue et al.

[21] Appl. No.: 269,368

[57] ABSTRACT [30] F i A fi afi P i i D A lamp arrangement for medical operating rooms. Light from a point source is focused by a spheroidal 11 7,1971 G ..P21 33 719.9

u y ermany reflector on the inlet end of a hght pipe, whlch trans- 521 11.s.c1 240/14 240/1 EL 240/4115 it to a reflector arrangement below- 240/41; bodiment a straight light pipe is employed with a 511 1m. 01 A6lg 13/00 Stepped Prismatic element direct the light upward [58] Field 61 Search 240/14 1 EL 41.15 a Stepped reflecm alemate embmjimem a 240/411, 350/96 R curved light pipe is employed to transmit the light directly onto a parabolic reflector, The light rays leaving [56] References Cited the final reflector in both embodiments are parallel UNITED STATES PATENTS and of uniform intensity.

3,536,908 10/1970 Oster 240/] EL X 8 Claims, 2 Drawing Figures OPERATING LAMP PROVIDED WITH A LIGHT PIPE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a medical operating room lamp provided with a light pipe for the low loss transmission of light rays or current from a light source to the operating area.

2. Description of the Prior Art The problem of eliminating shadows from a medical operating room area is generally solved by providing several lamps which combine to form one large operating lamp and illuminate the operating area from different angles. The absence of shadow does not imply the lack of any gradation of light produced by obstacles in the beam pathof the light, but the avoidance of shadow which occurs even when only one light source is partially covered. The operation of several operating lamps combined to form one lamp ensures the absence of shadow without restricting the vision.

In the case of an operating lamp of the above type it has been proposed to arrange the individual lamps along a circular ring, open at one point, and around an operating lamp provided in the center of the circular ring. Each operating lamp forms a unit provided with a cooling arrangement through which flows a refrigerant. Since the operating lamps are provided with cooling means, light sources with particularly high intensity bulbs can be used. In spite of their good light yield, these bulbs were previously unusable for illuminating operations due to the particularly high explosion risk of the gases used in medical operations. As a result of the cooling arrangement, the dimensions of the bulbs in the proposed operating lamps may be smaller than usual, thus relieving the psychological burden on the part of the surgeon who has hitherto felt himself spacially restricted by the plurality of lights being housed in one large common lighting unit.

When using a single operating lamp to illuminate the operating area, the problem arises of having to fan out the beams from the lamps and direct them onto the operating area with approximately the same intensity.

SUMMARY OF THE INVENTION According to the invention, this problem is solved by the operating lamp being such that a light pipe forms the optical connection between a light bulb reflector and the operating lamp reflector arrangement located.

below it. This reflector arrangement serves to change the direction of the light before it impinges on another reflector radiating beams onto the operating area.

The light pipe used as a connection between the reflector and a fur ther reflector arrangement is, for example, in the form of an endoscope typically used for illuminating the actual cavities of the body.

In addition, in a known operating lamp, several outlets arranged apart from one another are provided in the lighting unit. At least one common light source which is separate from the lighting unit is provided for all the light outlets. The light source is connected to the light outlets via at least one flexible light pipe. However, none of these solutions has provided a suggestion as to how to solve the problem of fanning out the light current discharged by an operating lamp having-a small illumination range and thus of increasing the illumination range while retaining as far as possible the same light intensity.

The reflector arrangement consists advantageously ofa prismatic element having at least two inclined sides offset from one another in the form of ascending saw teeth and a graduated reflector having an inner part and an outer part offset from it. The light pipe runs centrally through the reflector and is, for example, in the form of a straight glass rod. The beam is transmitted in this glass rod in the known way by total reflection.

For this purpose the inlet to the glass rod is disposed in a way known in itself, in the immediate proximity of the focusing point of a spheroidal reflector, said focusing point being disposed further away from the reflection layer. The glass rod outlet is spaced apart from the prismatic element. The glass rod transmits the light from the bulb to the reflector arrangement which converts the non-uniform light intensity issuing from the glass rod into a zone of approximately uniform intensity of illumination and reflects it onto the operating area. The prismatic element is preferably provided with a reflecting surface to deflect the rays of light from the glass rod in the direction of the graduated reflector. The geometry of the prismatic element and the graduated reflector is such that the inner sides of the prismatic body reflect the light rays onto the inner part of the reflector surrounding the glass rod, while the outer sides reflect the light rays onto the offset part of the reflector. The reflector parts reflect the light rays in a largely parallel manner in the direction of the operating area so that the originally diverging beams are converted into a uniform zone.

In a modified version of the invention the light pipe consists of a flexible fiber glass pipe, which receives the light from the operating lamp, transmits it in the known way by total reflection and reflects it into the reflector arrangement consisting of a full-parabolic reflector. The fiber glass pipe advantageously forms a question mark shaped semi-curve with vertical end sections, the light inlet and outlet faces being horizontal and parallel to one another. The lower end section curves in the direction of the upper end section and is in alignment with the same. A common perpendicular line passes through the light inlet and outlet faces of the fiber glass pipe and through the light source of the operating lamp.

By arranging a light pipe between the reflector immediately surrounding the light source of the operating lamp and the reflector arrangement, the'distance between the operating lamp and the reflector arrangement may be selected as desired. The advantage of this is that the size of the illumination area may be varied very easily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic sectional view of an operating lamp according to the invention, having aglass rod as light pipe; and

FIG. 2 is a diagrammatic sectional view of another embodiment with a fiber glass pipe as light pipe.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment shown in FIG. 1, the light is transmitted from a bulb 12 of an operating lamp 10 onto the operating area by means of a glass rod 20, a prismatic element 24 and a graduated reflector 28. The bulb 12 is disposed in a known way in a focusing point of a spheroidal reflector mirror 14. The operating lamp 10, may as has already been proposed, be surrounded by a refrigerator box, which is constantly flushed by a pressurized refrigerant.

The rays which do not enter the glass rod directly, are collected by the reflector 14 in a second focusing point. The reflector 14 is of such type that the infra-red rays penetrate to a large extent through its reflection layer and only the remaining rays are reflected. To this end, the reflector 14 is constructed in the known way as a cold light mirror with a reflection layer 16 which only allows the passage of infra-red rays. The reflected rays 18 are collected in a second focusing point of the spheroidal reflector 14. The second focusing point is located inside the glass rod 20 in the immediate proximity of the glass rod inlet. This focusing point or line is in the vertex of the angle within which all the rays 18 in the glass rod are transmitted by total reflection. The outside of the totally reflecting glass rod 20 may be covered with a reflecting coating to prevent light rays from escaping from the glass rod 20. Synthetic glass or other light conductive materials may obviously be used in place of ordinary glass.

The glass rod 20 passes through the reflector 28 which surrounds it. The outer part of this reflector is offset in a stepped manner from the inner part. Together with the prismatic element 24 the reflector 28 forms a reflector arrangement, which makes possible the transmission of light from the bulb 12 to the operating area. The rays of light 22 issuing from the glass rod 20 are divergent and impinge on the prismatic element 24 disposed at some distance from the glass rod outlet. This prismatic element 24 has at least two inclined sides offset from one another. In section and seen from the side these look like saw teeth, the base points of which lie on an ascending line. The inner sides of the prismatic element 24 form a cone. The prismatic element 24 is closed off by a level base. All the rays 22 impinging on the prismatic element 24 are reflected and radiated into the reflector 28. In the course of this, the rays 22 impinging on the inner cone of the prismatic element 24 are radiated into the inner part of the reflector 28 and the rays 22 impinging on the outer sides of the prismatic element 24 onto the outer part of the reflector 28. The geometry of the prismatic element 24 and the graduated reflector 28 is such that the inner and the outer part of the reflector 28 reflect the light rays 26 in parallel in the direction of the operating area, in the form of rays 30. Since the light coming from the bulb 12 via the reflector 14 first passes through the glass rod 20 and is reflected from there via the prismatic body 24 and the graduated reflector 28 onto the operating area, the non-uniform light intensity can be transformed into a zone of approximately uniform intensity of illumination. It is thus possible to obtain a uniform distribution of light over the operating area from an initially small illumination zone with a nonuniform light intensity resulting from the small dimensions of the reflector 14 by reflecting the light rays into the glass rod 20, by reversing them by means of the prismatic element 24 and by beaming them into the reflector 28 which is substantially larger than the reflector 14.

FIG. 2 shows an alternate embodiment of the operating lamp 10. Instead of a glass rod 20, this is provided with a fiber glass pipe 32. A prismatic element 24 is not required in the case of this embodiment. Components which correspond to those in FIG. 1 have not been assigned reference numbers in FIG. 2. The light rays coming from the reflector are likewise collected in the second focusing point of the reflector located in the fiber glass pipe 32 in the immediate proximity of the light inlet. The passage of the light rays through the fiber glass pipe 32 continues in the known way by total reflection. The outside of the fiberglass pipe 32 may be covered with a reflecting coating to prevent light rays from escaping from the pipe. The fiber glass pipe 32 re ceives the light from the bulb or from the reflector and beams it into a parabolic reflector 36. The light inlet and outlet faces are horizontal and parallel to one another. The lower end section is curved in the direction of the upper end section and is in alignment with the same.

The fiber glass pipe 32 passes to the side of the reflector 36 and its lower end is trained on the reflector 36. The focusing point of the parabolic reflector 36 lies within the lower end of the fiber glass pipe 32, in the immediate proximity of the light outlet face of the same. Synthetic glass or other light conductive materials can obviously be used in place of natural glass. The angle of incidence of the light rays entering the fiber glass pipe 32 is such that all rays within this angle are passed on within the fiber glass pipe 32 by total reflection. The light rays 34 emerging from the fiber glass pipe 32 impinge in a divergent manner on the reflector 36 and are reflected onto the operating area as parallel light rays 38. The direction of the light rays is reversed by the question mark shaped fiber glass pipe 32 and the rays are fanned out by reflecting onto the reflector 36. As a result, an enlarged radiation field is obtained as compared to the field obtainable with the upper bulb reflector alone. Furthermore, the intensity of the light issuing from the fiber glass pipe 32 is converted into a field of practically uniform intensity of illumination. This light intensity was initially of a non-uniform nature. A perpendicular line runs through the end faces of the fiber glass pipe 32. An imaginary extension of this line passes through the bulb.

By using the glass rod 20 or the flexible fiber glass pipe 32 as the optical connection between the reflector 14 of the bulb 12 and a reflector arrangement of the operating lamp 10, the distance between the bulb 12 and the reflector 28 or 36, reflecting directly onto the operating area, may be selected as desired. The reflector arrangement of the operating lamp 10 is located below the reflector of the bulb l2 and consists of the prismatic element 24 and the graduated reflector 28. It may only consist of the parabolic reflector 36. In addition, it is also possible for the reflector 28 or 36 to be relatively large as compared to the reflector of the bulb 12, so that a correspondingly broad field of illumination is obtained.

The fiber glass pipe 32 may also be connected to a known operating lamp by means of an adapter (not shown), to direct the light onto the operating area.

What is claimed is:

1. In an operating lamp having alight pipe for the low loss transmission of light from alight source to an operating area, the the improvements characterized by:

a. a first reflector optically cooperable with the light source,

b. a reflector arrangement including a second, graduated reflector disposed below the first reflector and above an operating area, and having an inner part and an outer part which is offset from it,

c. the light pipe being arranged to transmit light collected from the source by the first reflector to the reflector arrangement, and

d. means for reversing the direction of the light before it impinges on the second reflector comprising a prismatic element having at least two inclined sides offset from one another in the form of saw teeth.

2. An operating lamp according to claim 1, wherein the light pipe passes cenrally through the graduated reflector and is in the form of a glass rod in which the rays are transmitted by total reflection.

3. An operating lamp according to claim 2, wherein the glass rod inlet is located in the immediate proximity of the focusing point of the first reflector, and the glass rod outlet is spaced from the prismatic element.

4. An operating lamp according to claim 3, wherein the prismatic element has a reflecting surface to reflect the beams of light issuing from the glass rod onto the graduated reflector.

5. An operating lamp according to claim 4, wherein the geometry of the prismatic element and the graduated reflector are such that the inner sides of the prismatic element reflect the light rays onto the inner part of the graduated reflector surrounding the glass rod, the outer sides reflect the light rays onto the offset part of the graduated reflector, and the graduated reflector parts reflect the light in parallel in the direction of the operating area.

6. In an operating lamp having a light pipe for the low loss transmission of light from a light source to an operating area, the improvements characterized by:

a. a first reflector optically cooperable with the light source,

b. a reflector arrangement including a second, parabolic reflector disposed below the first reflector and above an operating area,

c. the light pipe being a flexible fiberglass pipe having one end positioned to receive light collected from the source by the first reflector and the other end positioned at the focal point of the parabolic reflector to transmit the collected light thereto, the light pipe being curved to reverse the direction of the light before it impinges on the parabolic reflector.

7. An operating lamp according to claim 6, wherein the fiber glass pipe forms a question mark an S-shaped half loop with vertical end sections, the light inlet and outlet faces of which are horizontal and parallel to one another, the lower end section being curved in the direction of the upper end section and in alignment with the same.

8. An operating lamp according to claim 7, wherein a common perpendicular line at the two end facesof the fiber glass pipe passes through the light source. 

1. In an operating lamp having a light pipe for the low loss transmission of light from a light source to an operating area, the the improvements characterized by: a. a first reflector optically cooperable with the light source, b. a reflector arrangement including a second, graduated reflector disposed below the first reflector and above an operating area, and having an inner part and an outer part which is offset from it, c. the light pipe being arranged to transmit light collected from the source by the first reflector to the reflector arrangement, and d. means for reversing the direction of the light before it impinges on the second reflector comprising a prismatic element having at least two inclined sides offset from one another in the form of saw teeth.
 2. An operating lamp according to claim 1, wherein the light pipe passes cenrally through the graduated reflector and is in the form of a glass rod in which the rays are transmitted by total reflection.
 3. An operating lamp according to claim 2, wherein the glass rod inlet is located in the immediate proximity of the focusing point of the first reflector, and the glass rod outlet is spaced from the prismatic element.
 4. An operating lamp according to claim 3, wherein the prismatic element has a reflecting surface to reflect the beams of light issuing from the glass rod onto the graduated reflector.
 5. An operating lamp according to claim 4, wherein the geometry of the prismatic element and the graduated reflector are such that the inner sides of the prismatic element refLect the light rays onto the inner part of the graduated reflector surrounding the glass rod, the outer sides reflect the light rays onto the offset part of the graduated reflector, and the graduated reflector parts reflect the light in parallel in the direction of the operating area.
 6. In an operating lamp having a light pipe for the low loss transmission of light from a light source to an operating area, the improvements characterized by: a. a first reflector optically cooperable with the light source, b. a reflector arrangement including a second, parabolic reflector disposed below the first reflector and above an operating area, c. the light pipe being a flexible fiberglass pipe having one end positioned to receive light collected from the source by the first reflector and the other end positioned at the focal point of the parabolic reflector to transmit the collected light thereto, the light pipe being curved to reverse the direction of the light before it impinges on the parabolic reflector.
 7. An operating lamp according to claim 6, wherein the fiber glass pipe forms a question mark an S-shaped half loop with vertical end sections, the light inlet and outlet faces of which are horizontal and parallel to one another, the lower end section being curved in the direction of the upper end section and in alignment with the same.
 8. An operating lamp according to claim 7, wherein a common perpendicular line at the two end faces of the fiber glass pipe passes through the light source. 